Australian Open: Players at the limit warns Novak Djokovic

The thermometer edged towards 40C in the shade as Djokovic and Monfils took to a sun-baked Rod Laver Arena for their second-round match, which the six-time champion eventually won 4-6 6-3 6-1 6-3.

Monfils began to really suffer during the second set, repeatedly doubling over and not even attempting to return serve during one game.

The Frenchman rated the conditions the toughest he has ever played in, saying: “For sure, we took a risk. I got super dizzy. I think I had a small heat-stroke for 40 minutes. I tried to cool down. But even with the ice towel, the water, I think my body was super warm.”

Djokovic said: “You work and train hard to be able to sustain these kind of conditions, to be tough. But I think there is a limit, and that is a level of tolerance between being fit and being in danger in terms of health. It was right at the limit. Our sport has become an industry, like most of the other global sports. It’s more business than a sport. At times, I don’t like that.”

Stan Wawrinka’s comeback ended with a second-round 6-2 6-1 6-4 loss to Tennys Sandgren.

Fifth seed Dominic Thiem showed tremendous mental and physical resilience to defy the conditions and come from two sets down to beat Denis Kudla 6-7 (6/8) 3-6 6-3 6-2 6-3.

There was a big shock as seventh seed David Goffin was beaten 1-6 7-6 (7/5) 6-1 7-6 (7/4) by French veteran Julien Benneteau, who is playing at Melbourne Park for the final time.

Juan Martin del Potro was also tested but defeated Russian Karen Khachanov 6-4 7-6 (7/4) 6-7 (0/7) 6-4.